The present invention relates to an electromagnetic clutch device, an actuator device, and a controller for controlling an opening and closing body for a vehicle.
Generally, an electromagnetic clutch device includes an armature and a rotor. The armature is supported by a driving member so that the armature is movable in the axial direction and rotates integrally with the driving member. The rotor is arranged coaxially with the armature, rotates with respect to the armature, and rotates integrally with an output member. In the electromagnetic clutch device, the armature and the rotor are pressed against each other based on the electromagnetic attraction force generated by an electromagnet. This couples two rotators (i.e., the armature and the rotor) in a torque transmittable manner.
In such an electromagnetic clutch device, generally, the gap between the armature and the rotor, which face each other, is set to a value as small as possible. This is because the broader the gap between the armature and the rotor is, the greater the contact sound generated by contact between the armature and the rotor becomes. Accordingly, for example, in the electromagnetic clutch device disclosed in Japanese Laid-Open Patent Publication No. 2008-95704, a damping member formed of a viscoelastic material is located between the driving member and the armature. The armature is urged based on the elastic force of the damping member in the axial direction so that the armature contacts the rotor. This limits the generation of the contact sound.
However, if the gap between the armature and the rotor is reduced as described above, relative rotation may be caused in a decoupled state between the armature and the rotor while sliding on each other due to reverse input from the output member. At this time, there is a problem that an abnormal noise occurs according to the stick-slip phenomenon, in which the friction surfaces of the armature and the rotor are microscopically fixed to and slide on each other.
In consideration of such a problem, in the the electromagnetic clutch device disclosed in the above publication, the damping member is fixed to the armature. This maintains the contact state between the damping member and the armature and efficiently reduces the vibration of the armature, which improves the muting effect (silencing effect).
As for further improvement of the silence, the fact is that even the silencing effect in the above described prior art cannot be recognized as sufficient. Accordingly, a more effective silencing structure is desired. In this respect, the electromagnetic clutch device of the publication has room for improvement.